Ball — On the Method of Regulating a Clocli. 67 





Seconds of Mean Time Clock at True Mean Koon to-dat. 







58-0 58'5 



59-0 o9-5 0-0 



I 



o-o 1-0 



1-5 



2-0 



'A 

 9 

 3 



H 

 'A 

 r^ 



o 

 < 



H 

 < 



o 

 1^ 



H 



H 



< 



o 



m 

 O 

 i<5 

 O 

 O 

 W 

 02 



o 



+ 2-0 



+ 1-0 



.+ 0-0 



- 1-0 



-2-0 



-3-0 



-4-0 



-5-0 



-6-0 



o 

 do 



1.0 



+ 2-5 



+ 1-5 



+ 0-5 



- 0-.5 



- 1-0 



-2-5 



- 3-0 



-4-0 



— b'b 





+ 3-0 



+ 2-0 



+ 1-0 



0-0 



-ro 



- 2-0 



-3-0 



-4-0 



-o-o 





+ 3-5 



+ 2-0 



+ 1-0 



+ 0-O 



- G-o 



- 1-5 - 2-5 



- 3-5 



-4-0 



o 

 o 



+ 4-0 



+ 3-0 



+ 2-0 



+ 1-0 



+ 0-0 



-1-0 



-2-0 



- 3-0 



-4=0 

 -3-0 



o 



+ 4-5 



+ 3-5 



+ 2-5 



+ 1-0 



+ 0-5 



- 0-5 



- 1-5 



-2-0 



p 



+ 5-0 



+ 4-0 



+ 3-0 



+ 2-0 



+ 1-0 



0-0 



- 1-0 



-2-0 

 - 1'5 



- 3-0 



- 2-0 



p 



+ b-b 



+ 4-5 



+ 3-0 



+ 2 -.5 



+ 1-0 



+ 0-5 



-O'o 



+ 6-0 



+ .5-0 



+ 4-0 



+ 3-0 +2-0 



+ 1-0 



0-0 



- 1-0 



1 



-2-0 



Por example, at mean noon to-day the clock showed llh. 59m. 

 59-Os., while yesterday it showed Oh. Om. O'Ss., then the table gives 

 + 2-5, which means that weights equivalent to 2*5 seconds should be 

 placed on the shelf, to make the clock right to-morrow. 



_ In order to facilitate the application of this correction fifteen cylin- 

 drical brass weights have been made. These cylinders have weights 

 corresponding to 3, 6, 9, 10, 10-5, 11, 11-5, 12, 12-5, 13, 13-5, 14, 

 14-5, 15 seconds respectively. 



In starting the clock, it is rated by the pendulum bob, in the usual 

 way, to go as nearly accurately as possible when the 12-5 second 

 cylinder, and also the 6 second cylinder are both on the shelf. The 

 latter will not be altered, unless in the case of a considerable change 



p 2 



